(171 



Popular Science Monthly 



There are no exposed levers or flywheels 

 and the motor is enclosed in a casing 



A Tiny Portable Hoisting Engine of 

 Dual Power 



ADliMIM'TIVK Init powerful hoist- 

 ing engine that handles loads of one 

 thousantl ixunids or less o\er distances of 

 sc\eral hundretl feet has been de- 

 signed recent !>'. It is ojicratet' 

 either by steam or by com- 

 pressed air. 



This little iioist, said 

 to be the smallest prac- 

 tical one of its kind, 

 has the additional fea- 

 ture of safety, ha\ing 

 no exposed levers or 

 flxAvheels. 1 1 is design- 

 ed for rough ser\ice, 

 particularK- for use in 

 mines and cjuarries. 

 It is portable, and can 

 be mounted almost 

 anywhere — clamped 

 to a pipe (jr cokinni or 

 bolted to the wall. 



Both for safet\- and 

 motor is contained in 

 brake is a band-l\pe operated by a worm 

 — a screw with a long pilch — to constrict 

 it, so as to give greater holding power. 



Why the Rain Follows the Thunder 

 and Lightning 



WHY does a hea\y downpour of 

 rain often follow a clap of 

 tiiunder? Xot, as is popularly be- 

 lie\ed, because the thunder jostles the 

 cioiid particles together into raindrops. 

 In the \iolenl turmoil between the 

 pi)siti\e and negati\e electricity in a 

 tiiiindercloud there will be places 

 where the production of drops, by con- 

 densation, and their subseciucnl break- 

 ing up proceeds more rapidly than 

 elsewhere. Hence in these places 

 tliere will be more drojis to fall as 

 rain, and also more electrification, 

 the rainfall occurring about the same 

 time as the Hash. We have, then, 

 starling toward the earth at the 

 same lime, light, sound, and raindrops. 

 The light, traveling at a speed of about 

 i,S6,ooo miles per second, reaches us 

 almost instantly. The sound travels 

 far more slowK" — about 1,090 feel per 

 second — but the rain falls much slower 

 still. Thus we obser\e, first, the light- 

 ning, then the thunder, and then rain. 



The paper is pulled out and the 

 eilne ol' the box-cover cuts it 



lirai)lllt\'. 



casiTig. 



Ihe 

 The 



A Tobacco-Can with a Roll of Cigarette 

 Papers Attached to It 



FOR the conxenience of smokers who 

 prefer to roll their own cigarettes, 

 Bertram .A. Rose, of Fort Worth, Texas, 

 has invented a cigarette-paper 

 holder attached to the under 

 ide of a tobacco-can co\-er. 

 When he wants to roll a 

 cigarette the smoker 

 jnills the paper out- 

 ward and downward 

 Irom its position on 

 the roller, and then 

 tears it oil for a long 

 or short smoke b\' us- 

 ing the outiT edge of 

 I he lid as a cutter. 



In pulling the paper 

 otitward and down- 

 ward o\er the edge of 

 the lid the "roll" is 

 t.iketi out. The paper 

 m.i\' be ])erforaled to 

 facilitate the tearing and cutting oiiera- 

 tion, but the in\entor relies m.iinly 

 upon the outer edge of the lid for cutting 

 each piece of jiaper as it is pulled from 

 the roll anil pre.sse<l against the tin. 



